Of course you can not trust the full rating sites. But you can use them as a primary source. It is necessary to allocate projects with sufficient rating and study them further. For me, the most important parameter is the publicity and activity of the team. The presence of experienced professionals and a large number of hype.
All of the ratings are extremely biased opinions on how the coin should be. I don't care what they rate the coins, if I find it as a useful investment then I will invest in it.